About restrictions on antennas, there is a U.S. law/mandate that nobody can prohibit installing a flag pole of any size anywhere. Which shits on all HOAs.
Many toys can fit inside a fiberglass pole. But that is U.S.

 

https://www.fcc.gov/media/over-air-reception-devices-rule

 

Most of the earlier posters covered the major points. I want to emphasize that mast mounted pre-amps are inherently wide-band devices, as they are intended to cover all or most of the OTA frequency range. So it would be very unlikely a failure there would affect one channel,

Also, the noise figure of the second amplifier - the distribution amp - is a non-issue in 99% of the installs. The noise figure of the system is set by that of the first amplifier in the chain - the mast mounted amplifier (I assume this is mast mounted).

 

3-3-2022 - Again I want to thank all that have contributed! I installed my LTE/5G Filter last night and the results were "negative". This means the cell interference filter did not fix my problem. After a fairly detailed signal study of my entire system from my antenna to LTE/5G Filter, Pre-amp, Distribution-amp and all five wall outlets the signal strength is good (averaging in the -30s dBm). (See enclosed file). Based upon this study, I've concluded the interference is coming from somewhere else probably outside. Does anyone know anyone at the CIA, NSA or FCC or James Bond?

 

3-3-2022 - Again I want to thank all that have contributed! I installed my LTE/5G Filter last night and the results were "negative". This means the cell interference filter did not fix my problem. After a fairly detailed signal study of my entire system from my antenna to LTE/5G Filter, Pre-amp, Distribution-amp and all five wall outlets the signal strength is good (averaging in the -30s dBm). (See enclosed file). Based upon this study, I've concluded the interference is coming from somewhere else probably outside. Does anyone know anyone at the CIA, NSA or FCC or James Bond?

Where did you put the 5G filter? It doesn't make sense that the signal strength of NBC 5.1 would be stronger after the filter,-62.4 dBm, which I assume is passive, than after the antenna (and before the filter), -64.4 dBm.

 

LOss of good reception on one channel only, and at such a critical moment? That sounds like an interfering signal. Like somebody just added an amplifier to their system and it is oscillating and radiating a signal that is disrupting your reception.

 

Hi Stevesh! The LTE/5G Filter is at the end of 6' of Coax coming directly from the antenna. The Filter is installed just before the Pre-Amp. I also saw the small signal drop in signal strength as you did but assumed the filter effected signal strength .

 

Sorry second try....system timed out.
Hi Stevesh! The LTE/5G Filter is at the end of 6' of Coax coming directly from the antenna. The Filter is installed just before the Pre-Amp. I also saw the small change in signal strength as you did but the filter positively affected NBC (530 Mhz) signal strength from -64.4 dBm to -62.6 dBm. We have to remember the bigger the negative number the worse the reception. Although -62.6 is bad reception, it is still better than -64.4 dBm. Very confusing!
However, if you noticed the 180 Mhz reading for ABC received worse reception after the Filter (-64.3 dBm vs. -66.3) and also for FOX on 500 Mhz (-61.2 dBm vs. -63.0). These are small variances and could be caused by erratic and cheap meter readings?

Hi MrBill2, I agree with you. My problem is caused by interference. I'd bet $100.00 not from within in my house because no electronic devices have changed or added in the last two years (except an iPhone upgrade from 6 to 12) when my full system has worked perfectly. Even with the new LTE/5G Filter installed and the new iPhone 12 turned off, I still get interference. I've recently noticed on a FCC Web Site they have licensed 821 organizations to broadcast in a frequency spectrum that includes 530Mhz in the U.S. It doesn't specify "Dallas" but "Fhat the Wuck"! How am I going to figure out which one is causing the interference? Spend $1M on a tractor trailer truck and a stack of electronic surveillance equipment? Yea Right! Then after I've figured out who the culprit is, what can I do about it? Probably nothing! I've about given up....only God, Allah or Budda knows the real answer!

 

Tracking interference does not take a huge amount of expensive equipment if you are not in a rush. For a specif frequency, like the one channel, a portable receiver and a directional antenna are usually enough.
So my suggestion is to try a portable receiver with a directional antenna and work outside the house for a bit. An interfering signal will be stronger from some direction, and since you know where the transmitters are, you can verify which direction the desired signal is coming from. If the interfering signal is discernible, you can verify that your system is not the source just by switching off all of the powered segments, (preamp, distribution amp, and al other TVs)
That will give positive evidence one way or the other. Then you can know where to look next.
Chasing interference with a directional antenna is a lot easier if you have some indicator of the signal strength.

 

Tracking interference does not take a huge amount of expensive equipment if you are not in a rush. For a specif frequency, like the one channel, a portable receiver and a directional antenna are usually enough.
So my suggestion is to try a portable receiver with a directional antenna and work outside the house for a bit. An interfering signal will be stronger from some direction, and since you know where the transmitters are, you can verify which direction the desired signal is coming from. If the interfering signal is discernible, you can verify that your system is not the source just by switching off all of the powered segments, (preamp, distribution amp, and al other TVs)
That will give positive evidence one way or the other. Then you can know where to look next.
Chasing interference with a directional antenna is a lot easier if you have some indicator of the signal strength.

I must just comment
on how different the US to Europe

Over this side of the water,
if there is the suspicion of interference,
you pay a set ( relatively small fee ) the the authorities are out having a snoop around
and, if they find interference, you get your money back

good luck finding

 

Hi Stevesh! The LTE/5G Filter is at the end of 6' of Coax coming directly from the antenna. The Filter is installed just before the Pre-Amp. I also saw the small change in signal strength as you did but the filter positively affected NBC (530 Mhz) signal strength from -64.4 dBm to -62.6 dBm. We have to remember the bigger the negative number the worse the reception. Although -62.6 is bad reception, it is still better than -64.4 dBm. Very confusing!
However, if you noticed the 180 Mhz reading for ABC received worse reception after the Filter (-64.3 dBm vs. -66.3) and also for FOX on 500 Mhz (-61.2 dBm vs. -63.0). These are small variances and could be caused by erratic and cheap meter readings?

While I don't think this is related to your problem, in general you want the pre amp as close to the antenna as possible. Any filters, splitters, etc should go after the pre amp. This is because you want to minimize any losses between the antenna and the pre amp. The only time you would deviate from this setup is if you had a very strong interferer that might cause your pre amp to compress/saturate (go into non-linear operation). When this happens,the pre amp can become a mixer and generate lots of unwanted frequency products (spurs).

 

I must just comment
on how different the US to Europe

Over this side of the water,
if there is the suspicion of interference,
you pay a set ( relatively small fee ) the the authorities are out having a snoop around
and, if they find interference, you get your money back

good luck finding

Here in the USA we have the FCC, which is usually busy with other matters. AND, if the problem is with one's own system, it is better to keep the matter private and solve it one's self.